What are technologies that can assist in both employee engagement and measurement of success of employee engagement?

There is a segment of commercial products that do this.  CultureIQ is one I did some work with.  I've also seen the solution from McLean & Company in action:  https://hr.mcleanco.com/hr-diagnostics/engagement-program

Surveys, performance plan (below/meet/exceed) criterion and continues service feedback collection could be a comprehensive combination to both align and measure employees engagement.

Im open to corrections.

Adaption or build the platform powered by machine learning & AI. 

Technology specific to engagement... we lean heavily on anonymous surveys by segment 

We have what’s called performance measurement plans that we create with our staff in a quantitative way. This allows them to meet or exceed those expectations and that’s what their annual performance review is based on. We also do a mid year follow-up and we can also meet throughout the year.